yeah I think using the body is the way to go. On this particular homepage there is no body at all, it’s all containers.
A quick test on my local pre prod machine with page rendering time:
as a decorator the postprocess process a string with a length of:
no rules - HTML length: 22977 (800ms)
with rules on - HTML length : 133799 (4000ms)
Just applied to body:
no rules - HTML length: 0 (400ms)
with rules - HTML length: 0 (500ms)
My pre prod machine handles the postprocess much better than the prod machine which takes up to 30 - 40 secs with rules on.